This invention is the subject matter of Disclosure Document No. 083980, filed in the U.S. Patent and Trademark Office on behalf of applicant on Sept. 4, 1979.
Track maintenance for railroads and the like has always been a costly and time-consuming operation involving an inordinate amount of manual labor. Such maintenance however is essential in order to assure safe, efficient, smooth, and expeditious movement of trains along the track. Customarily, the track includes a pair of steel rails arranged in a predetermined spaced parallel relation with the base of the rails secured to and supported by a plurality of wooden cross ties substantially uniformly spaced along the rails. The ties rest up a road bed normally formed of a layer of crushed stone or rock called ballast. Securement of the base of each rail to the tie is normally effected by a rail plate which subtends a portion of the rail base and is disposed within an adzed recess formed in the upper surface of the tie. The upper surface of the rail plate is provided with a recessed area sized to receive the bottom surface of the rail base. Suitable openings are formed in the rail plate to receive spikes which are driven into the tie and secure the rail plate to the tie. The location of certain of the openings in the rail plate is such that the spikes accommodated in the openings will have the heads thereof overlying and pressing against an adjacent toe or peripheral portion of the rail base.
Because of the tendency of the rails to spread apart when a train moves over the track, it has been customary, in the past, to utilize lateral rail anchors and gauge bars in conjunction with the ties and rail plates to resist such relative movement and to maintain the rails in proper parallel spaced relation.
Oftentimes to expedite and/or to minimize material and labor costs involved in track maintenance, potentially dangerous track conditions are created due to (a) a minimum number (e.g., a single spike) of spikes being utilized to secure the rail plate and rail to the tie surface; (b) the spikes are not driven to their fullest extent into the supporting tie; and (c) the spike-holding power of the tie is weak and ineffective due to the age and physical condition of the supporting tie. Under any of these conditions and depending upon the amount and speed of the traffic moving over the track, the rail and rail plate will in a relatively short period of time cause increased relative movement of the rail with respect to the tie due to traffic vibrations and/or expansion and contraction of the components caused by temperature variations resulting in misalignment of the rails and ultimately a derailment.
Heretofore in an effort to reduce the occurrence of these conditions and the hazards associated therewith, various forms of rail hold-down devices or assemblies have been proposed; however, because of certain inherent design characteristics they have been beset with one or more of the following shortcomings: (1) the device or assembly was of a costly and complex construction; (2) attachment of the device or assembly to the rail and tie was an awkward and difficult manipulation or procedure oftentimes requiring the talents of highly-skilled and experienced labor; (3) the device or assembly was not capable of being used with various types and sizes of ties and rails; (4) the device or assembly required an inordinate number of customized accessories to effect proper securement of the rail to the tie; (5) the device or assembly could not be readily removed from the tie or rail, when required, without causing serious mutilation, defacement, and damage to the rail and/or tie; and (6) the device or assembly was susceptible to vandalism and sabotage.